Stereoscopic projection systems have been developed that are based on the presentation of different images to an observer's left and right eyes. Typically the different images are associated with different states of polarization of corresponding light fluxes, and the observer is provided with eyewear that contains polarizers oriented so that each eye receives only the appropriate light flux. For example, images for a left eye and a right eye can be presented in orthogonal, linear states of polarization, and eyewear provided with suitably configured linear polarizers.
Stereoscopic images can be provided for entertainment, industrial, or scientific purposes. Examples of such images include stereoscopic travel images, images for video or other games, and viewing of three dimensional models of chemical or biological systems that are under investigation. Frequently, such images are to be presented to groups of observers to provide a common viewing experience and the images are preferably projected onto a projection screen or other surface. Unfortunately, conventional projection screens and other surfaces are often unsuitable because an incident light flux is partially or completely depolarized by the projection screen so that the stereo viewing effect is severely degraded. While a few suitable stereo projection screens are commercially available, these screens are fragile and require special handling, set-up, and maintenance. In addition, very large screens tend to be difficult to manufacture, and are too expensive for many potential applications. Non-planar screens are even more problematic. In spite of the increasing interest in and the development of stereo imaging systems, durable projection screens for stereo imaging continue to be unavailable. Described below are several solutions to these long standing problems.